Merge lp:~laurynas-biveinis/percona-xtrabackup/BT-28340-1164979-2.0 into lp:percona-xtrabackup/2.0

[Laurynas Biveinis]

BT 28340

http://jenkins.percona.com/job/percona-xtrabackup-2.0-param/386/

Fix bug 1164979 (xtrabackup_56 can fail on prepare if log files > 4G
used on source server).

The issue is that log checkpoint offset field has been extended to 64
bits to support log files > 4G, yet XtraBackup would overwrite only
the lower 32 bits. If the higher 32 bits happened to be non-zero,
incorrect log offsets would be used for InnoDB recovery.

Fixed by overwriting the higher 32 bits with zero on MySQL 5.6.

[Alexey Kopytov (akopytov)]

review: Approve

=== modified file 'src/xtrabackup.cc'
--- src/xtrabackup.cc	2013-04-03 22:53:49 +0000
+++ src/xtrabackup.cc	2013-04-10 06:55:29 +0000
@@ -6349,6 +6349,10 @@
 			+ LOG_CHECKPOINT_OFFSET_LOW32,
 			LOG_FILE_HDR_SIZE + (ulint) ut_dulint_minus(max_lsn,
 			ut_dulint_align_down(max_lsn,OS_FILE_LOG_BLOCK_SIZE)));
+#if MYSQL_VERSION_ID >= 50600
+	mach_write_to_4(log_buf + LOG_CHECKPOINT_1
+			+ LOG_CHECKPOINT_OFFSET_HIGH32, 0);
+#endif
 #ifdef XTRADB_BASED
 	MACH_WRITE_64(log_buf + LOG_CHECKPOINT_1 + LOG_CHECKPOINT_ARCHIVED_LSN,
 			(ib_uint64_t)(LOG_FILE_HDR_SIZE + ut_dulint_minus(max_lsn,
@@ -6366,6 +6370,10 @@
 			+ LOG_CHECKPOINT_OFFSET_LOW32,
 			LOG_FILE_HDR_SIZE + (ulint) ut_dulint_minus(max_lsn,
 			ut_dulint_align_down(max_lsn,OS_FILE_LOG_BLOCK_SIZE)));
+#if MYSQL_VERSION_ID >= 50600
+	mach_write_to_4(log_buf + LOG_CHECKPOINT_2
+			+ LOG_CHECKPOINT_OFFSET_HIGH32, 0);
+#endif
 #ifdef XTRADB_BASED
 	MACH_WRITE_64(log_buf + LOG_CHECKPOINT_2 + LOG_CHECKPOINT_ARCHIVED_LSN,
 			(ib_uint64_t)(LOG_FILE_HDR_SIZE + ut_dulint_minus(max_lsn,